F irst identified in the 1970s by NASA's Viking mission, long, dark markings snake down Martian slopes, sometimes stretching ...

For years, researchers have pictured strange dark streaks running across the dusty Martian surface, with some thinking that ...

Water is considered an essential ingredient for life. Mars billions of years ago was wetter and warmer than it is today. The ...

Images taken of Mars from orbit dating back as far as the 1970s have captured curious dark streaks running down the sides of ...